Swiveling-roller gearing



March 8, 1927.

R. ERBAN SWIVELING ROLLER GEARING Filed June 26, 1926 2 Sheets-Sheet l March 8,1927. mmm

R. ERBAN SWIVEPING ROLLER GEARING Filed June 26. 1926 2 Sheets-Sheet 2 'mzwz Z 41/,

Patented Mar. 8, 1927.

7 UNITED STATES PATENT OFFICE RICHARD'ERI'BAN, or VIENNA, AUSTRIA.

swIvnLInG-RonLnR GEARING.

Application filed June 26, 1926, Serial No. 118,661, and in Austria September 21, 1925.

It has already been proposed in the case of 'gearings,,in which the power is transmitted from a race ring fixed on the dr1v.--

ing shaft by means of one or more rollers to race ring fixed on the driven shaft, to vary the gearing ratio by altering the diameters of the circles on which the rollers make contact withthe race rings. This is eifccted by swiveling the rollers about axeswhich intersect their axes of rotation and are parallel to the tangents at the points of contact between rollers and races. For I this purpose the race rings have a toric surface.

As, however, the rollers oifer a considerable resistance to being swiveled about such axes parallel tothe tangents, it has been proposed to effect the displacement of the roller indirectly by turning the. roller about an axis passing throughrthe points'of con tact of the roller with the race rings, so that the tangents at the roller in the points of contact no longer represent. tangents at circles on'the race rings, but atspirals, .The

-.t5rollers then move, according to the direction wards until they are turned back again into a position, in which the tangents 'of'the' rollers at the same time represent-tangents at circles on the race rings. Where a plurality I of rollers is used, however, itis almost impossible to bring all the rollers in this way on to the same circle on the races and tokeep them there, as even quite small angles, such as from 2 to 3', between theroller tangent and the running circle tangent sufiice for causing the, roller to. move along a spiral j path, a so-called drawing of the. roller.

v For overcoming this drawback the inventor has proposedfin his patentfapplication Ser. No. 35,988 to mount the-rollers with three degrees, of freedom of their rotar motion on spherical bearing members, pre. crably on'spherical ball bearings, and to stabilize them by their gyroscopic action and by means of the spherical ball bearing. Such a manner of mounting readily adjustable and is not adversely afi'ected by angular inexactness, if not'too great, so that the phenomenon of 4 drawing is not to be feared. When the rollers are displaced very rapidly, however, more particularly when the load is small, the stabilization of the rollersis not always suflicientfor ensuring the rollers being moved'with certainty -proaching and recedin part of The objectof the present invention is to provide tilting and displacing means, for enabling the rollers to be displaced rapidly at any device guides the roller which is somounted as to have three degrees of freedom of rotary motion in a similar manner for instance as the belt fork guides the belt. As experiments have shown, there is actually a certain similarity between the behavior of a roller running on race rings and that 'of a belt; at each point of contact and aproller may be differentiate and, exactly as it is very easy to displace a belt by acting with a fork on its approaching stretch and almost impossible to do so by acting" on the receding stretch, the roller very readily follows :a fork acting on its approaching part, while it is impossible to displace the roller by .acti ng onthe receding part. Thus, according to the invention each roller is provided-With a guiding devicewhich acts in the manner of a guiding fork on the roller, 'of rotation, in spiral paths outwards or'in guides-it into the desired path and keeps it there.

In the accompanying drawing several constructional, examples of the invention are shown. Figure 1 is a longitudinal section and Figure 2 a transverse section through a diagrammatic representation of: the ar-.

rangement. Figures 3 and 4 are an elevationand apla'n view respectively of a constructi'onal form for a definite direction of rotation. Figures 5 and 6 show a constructional form suitable, 'for'-both directions of rot'at-ion in elevation and'in'pl'an Figure 7' shows a-roller and a race-mug 111:!aXOI1Q- desired rate of speed, quite independently of the load on the gearing. This metric View. The other race ringis not shown, siinilarly to Figure 2'f' fori the sake 'of clearne's's. ForYthe same, reas'onfthe races are not shown at all" Figsl3to 6,

i. In Figures 1 a nd'2of the-drawing 1 isthe inner race ring, 2 the outer race ring and 3"the rollers which are rotatable about thespherical journals 4 of the axles l5. The

"latter are journalled in segment-shaped pieces 6, which are themselves guided in a known manner in radial slots in a'cage' which is not shown.- In Figures 1, and 7 the two straightlines which are perpendicular" to one anotherare drawn through thecentre 0 of. the upper side of the roller.' one of" which stralght lines P is parallel to the tangent on the race 1 in the point in the point M. 'lhese straight lines P and N are to be supposed as dividing the roller into four quadrnats a, b, and d. For the direction of rotation indicated by the arrows a and c are approaching and b and d J of the segments 6 lying opposite the part areceding parts of the roller.

On external pressure being applied to the approaching part a (or c) in the direction of the arrow a, Fig. 2l 01' an internal pressure in the direction of thearrow a the roller willfollow this pressure very easily and wvill set itself in the desired direction. It is 5 however impossible: to cause the roller. to move on to another running circle by exerting a pressure on one of the receding parts borcl. 5 I Figure 3 showsa roller witha guiding device in elevation, corresponding to Figure '2'. Figure 4 is the corresponding plan view.

It is assumed that thedirection of rotation is that shown by the arrow. The roller 3 is journalled by meansof the ball bearing 14 having a spherical outer race on the shaft 5 which itself rests in the segments 6-6. WVith'the assumed direction of rotation the part a which is the approaching part on M lies at the back and at the top, while the part b which is the part receding from M lies at the back and at the bottom. The edges are marked a and a: respectively. The edges Z1 6 which he opposite the receding part b are slightly set back, to prevent them touching the roller. Similarly the edges 0 0 cl d lying opposite the parts 0 and d are set back, as the edges a and a are sufficient for providing aguide. On. one of the segments 6 is a lug 9 to which a bar 10 is pivoted. By means-of this bar the-segments 6 are swivelled, the segments leading the roller 3 into its new position, as soon as the edges a or an, come in contact with it, 1 and keep the roller in this position. The a'r-' rangement described is perfectly satisfactory 5 where the direction of rotation always remainsthat indicated by the arrow, but is not suitable for the reverse direction of rotation, as in that case the edges a ar, would case all the edges are set back,-the surfaces 16 being milled oh the segments 6, which are the surfaces 16 are attached by means of screws 12 the guiding members 11, 11 so as to be capable of rotating easily, the middle portion of the two members being sli. htly recessed. On the segments 6 being disp aced by means of the bar 10, either the part 0 or the part 0 of one guiding member 11 lying opposite the approaching part 0 will first come in contact with the roller 8, in

which case the roller will immediately follow the pressure, or the edge (Z or (1 of one of the guiding vmembers 11 will-first make contact with the receding part (I of the roller, in which case the-roller will not follow the pressure, but the guiding member 11 will turn about. its pivot v12, until the edge or 0 comes in contact with the approaching part 0 of the roller, whereupon. the roller will readily follow the motion of the segments 6. It is obvious from the symmetrical arrangement of thi's'device that it will act for both directions of rotation in a similar manner. V

What I claim is: I

1. A device for displacingswivelmg roller gearings comprising incombination two race rings having toric surfaces, a plurality of rollers capable of-rolling between the said race rings, means for journalling the said rollers so as to have three degrees of freedom as regards their rotary motion, and guiding means for each roller capable of engaging with the approaching part of the roller, as set forth.

i 2. A device for displacing swiveling roller gearings comprising 1n combination two race rings having "toric surfaces, a plurality of rollers capable'of rolling between the said race rings, means for-journalling the said rollers so as to have three degrees of free-- dom as regards their rotary motion and a guiding fork for each roller which embraces the approaching part of the roller, as set.

forth.

3. A device for displacing swiveling roller gearmgscomplising in combination two race ringshavin toric surfaces, a plurality of rollers capa le of rolling between the'said' race rings, means .for journalling the said rollers so as to have three degrees offreedom as regards their rotary motion, a guiding fork for each roller which embraces the approaching part of the roller and guiding members mounted on the guiding fork so as to be rotatable about'journals parallel to the plane in whichtheroller rolls and which are,

therefore capable of coming in contact automatically with the part of the roller, which happens to be the approaching part, as set forth.

In testimony whereof I have hereunto set 

